1. Field of Use
This invention relates generally to rotary gas compressors having rolling pistons therein. In particular it relates to the construction and arrangement of the cylinder housing, cylinder chamber, vanes, suction ports, discharge valves, rotor assembly and seals employed in such compressors.
2. Description of the Prior Art
The prior art discloses various types of rotary gas compressors. Such compressors generally comprise a housing having a wall defining a cylinder chamber in which a roller piston mounted on an eccentric crankarm on a motor-driven shaft orbits in the cylinder chamber and rolls around the cylinder wall. The housing carries a reciprocably movable vane which is slidably mounted in a vane slot which communicates with the cylinder chamber and the vane slidably engages the roller piston. Gas enters the cylinder chamber through a suction port in the cylinder wall on one side of the vane slot. Compressed gas is periodically discharged from the cylinder chamber through a discharge valve mounted on the cylinder wall on the other side of the vane slot as the piston orbits and rotates. Single stage compressors usually employ one vane and an associated suction port and discharge valve. Multi-stage compressors employ a plurality of such vanes and associated suction ports and discharge valves. Multi-cylinder compressors, whether single or multi-stage, employ several cylinders and associated components in a ganged arrangement.
The following patents illustrate the state of the art of rotary gas compressors and related equipment. For example the following patents show multi-cylinder compressors or a plurality of compressors in stacked arrangement: U.S. Pat. Nos. 601,916; 4,012,181; 992,582; 1,053,767; 4,204,815; 1,083,710; 1,216,378.
The following patents show rolling piston-type compressors, some of which are two-stage: U.S. Pat. Nos. 2,226,191; 3,709,161; 2,535,267; 3,834,841; 2,552,860; 2,969,021; 3,683,694.
The following patents show valving arrangements in compressors and related equipment: U.S. Pat. Nos. 2,048,218; 2,394,166; 3,797,975; 4,183,723.
The following patent shows a common manifold for a plurality of compressors: U.S. Pat. No. 4,035,112.
The following patents depict compressor vanes of various types: U.S. Pat. Nos. 333,994; 3,280,940; 693,950; 1,649,256; 3,193,192; 3,259,306.
The following patents show piston constructions: U.S. Pat. Nos. 899,040; 1,216,378; 1,320,531; 3,976, 403.
Many prior art rotary gas compressors are so constructed that undesirable mechanical and operational problems are inherent therein. For example, some multi-cylinder compressors or ganged compressors employ an undue number of costly components of complex shape. Such compressors are difficult to manufacture and service and some employ many relatively movable parts which are subject to undue wear and breakdown, especially if lubrication systems are inefficiently designed. Some prior art multi-cylinder or ganged compressors employ rotor assemblies and rotors which create imbalance and vibration problems unless elaborate and painstaking balancing procedures and components are employed. Some prior art compressors employ relatively movable components, such as the vanes and discharge valves which are adversely or undesirably affected by gas pressure in parts of the system and reliability and efficiency are not at optimum levels. Some prior art compressors employ a type of gas discharge valve which is so constructed and located that there is incomplete expulsion of compressed gas from the piston chamber thereby resulting in system inefficiency and energy waste.
Other problems in prior art rotary compressors are identified and discussed in the aforementioned patents.